Graphene-coated polymer foams as tuneable impact sensors

Abstract

The use of graphene-based nanocomposites as electromechanical sensors has been broadly explored in recent times with a number of papers describing porous, foam-like composites. However, there are no reported foam-based materials that are capable of large dynamic compressive load measurements and very few studies on composite impact sensing. In this work, we describe a simple method of infusing commercially-available foams with pristine graphene to form conductive composites, which we refer to as G-foam. Displaying a strain-dependent electrical response, G-foam was found to be a reasonably effective pressure sensing material. More interestingly, G-foam is a sensitive impact-sensing material. Through the addition of various amounts of polymer filler, the mechanical properties of the composites can be tuned leading to the controllable variation of the impact sensing range. We have developed a simple model which quantitatively explains all our impact sensing data.

A reduced graphene oxide–borate compound-loaded melamine sponge/silicone rubber composite with ultra-high dielectric constant

“…50 This is due to the fact that the distance between conductive llers decreases to assist in the formation of a conductive network at low compressive strains, and then, the volume resistivity of the composite is reduced. 51 However, upon further increasing the compressive strain, the threedimensional conductive network causes a certain degree of damage such that the volume resistivity increases accordingly. The volume resistivity at 1.25 vol% has higher sensitivity to compressive strain as compared to that at the rGO volume fraction of 0.81 vol%, and the corresponding fractional resistance change (DR/R 0 ) at the compressive strain of 20% is À0.877, which is obviously superior to those reported in the literature.…”

“…The volume resistivity at 1.25 vol% has higher sensitivity to compressive strain as compared to that at the rGO volume fraction of 0.81 vol%, and the corresponding fractional resistance change (DR/R 0 ) at the compressive strain of 20% is À0.877, which is obviously superior to those reported in the literature. 51…”

Experimental and Analytical Investigation of Epoxy/MWCNT Nanocomposites: Electrical, Thermal Properties, and Electric Heating Behavior

“…Over the past years, carbon-based conductive fillers including zero-dimensional carbon blacks [3],one-dimensional carbon nanotubes (CNTs) [4,5], and carbon nanofiber [6], and twodimensional graphene or its oxide [7,8] have been employed to improve the electrical, thermal properties, and other physical properties of polymer-matrix composite due to their unique nanostructure and understanding physical attributes. As a result, conductive nanocomposites have been extensively applied in many advanced fields, such as shape-memory actuator [9], supercapacitors [10], pressure sensors [11,12], and electromagnetic interference (EMI) shielding [13]. Most recently, the polymermatrix composites filled with the carbon allotropes and their derivatives to achieve the heating functionality have attracted a lot of attention [14][15][16][17].…”

Ab Initio Design of Graphene Block Enables Ultrasensitivity, Multimeter‐Like Range Switchable Pressure Sensor

“…A 1000‐fold times resistance change can be realized within a pressure range of 1–70 kPa. Totally, the fabricated multimeter‐like pressure sensor shows a wide pressure range from <1 Pa to 72 kPa with different ultrahigh sensitivities using different sensing parts (15.22 kPa −1 for 0–300 Pa, 0.22 kPa −1 for 0.09–30 kPa, and 46.67 kPa −1 for 48–72 kPa), which present the prominent advantages in both the sensitivity and pressure range than some previous reports (Table S1, Supporting Information) …”

“…However, the pressure exceeding 300 Pa will influence the mechanical property of the rGO foam, thus bringing a poor recoverability. The rGO/PU foam–based sensor is one of the most widely used graphene‐based pressure sensors. The applied PU foam can improve the mechanical property and keep the good sensitivity of the rGO‐based sensor at the same time, but cannot handle the slight and tremendous pressures.…”